Design support method and design support device

Abstract

To facilitate consideration of effective structural measures using structural analysis using the finite element method.SOLUTION: A design support method includes: a stiffness index calculation step of calculating a distribution of stiffness indexes on a model by performing structural analysis by the finite element method when a load is applied to a specific load point, for the model of a frame member having an inner part having a closed sectional structure with a sectional polygonal shape and an outer part cooperating with the inner part to form a closed sectional structure with a sectional polygonal shape; a division step of dividing the calculated stiffness indexes into a plurality of ranges; and a reinforcement part specifying step of specifying, as a reinforcement part to be reinforced of the frame member serving as the model, a portion in which the stiffness indexes are in different ranges for the inner part and the outer part when a cross section of the model is obtained.SELECTED DRAWING: Figure 8

Claims

1. A method for supporting the design of frame members using a computer having a calculation unit, The calculation unit performs a stiffness index calculation step, which involves performing a structural analysis using the finite element method to calculate the distribution of stiffness indices on a model of a frame member having an inner part having a closed cross-sectional structure with a polygonal cross-sectional shape and an outer part cooperating with the inner part to form a closed cross-sectional structure with a polygonal cross-sectional shape, when a load is applied to a specific load point. The calculation unit includes a division step that divides the stiffness index calculated in the stiffness index calculation step into a plurality of ranges, The process includes a step of identifying a reinforcement area, in which, when a cross-section of the model is obtained, the portion where the stiffness index is in a different range between the inner portion and the outer portion is identified as a reinforcement area of ​​the frame member that has been modeled, which should be reinforced. The reinforcement area identification step involves identifying the areas in the ridge portion of the inner part and the ridge portion of the outer part where the stiffness index is in a different range as the reinforcement area. The design support method is characterized in that the reinforcement area identification step further includes identifying as the reinforcement area a portion where the distance between the portion of the ridge line of the inner part occupied by the stiffness index within a predetermined range and the load input point differs by a predetermined amount or more from the distance between the portion of the ridge line of the outer part occupied by the stiffness index within a predetermined range and the load input point.

2. In the design support method described in claim 1, The aforementioned frame members are numerous and connected to one another to form a vehicle body. The aforementioned model mimics a vehicle body constructed by connecting the multiple frame members to each other. A design support method characterized in that the load input point is set at the end of each model of each frame member that is closest to the specific load point.

3. In the design support method according to claim 1 or 2, The reinforcement step further includes setting a reinforcing portion that connects the ridge portion of the inner portion and the ridge portion of the outer portion in the reinforced portion, The design support method is characterized in that the reinforcement step is a step of setting the reinforcing portion to extend in the direction in which the frame member extends so as to include the reinforced portion.

4. In the design support method described in claim 3, The aforementioned frame members are numerous and connected to one another to form a vehicle body. The aforementioned model mimics a vehicle body constructed by connecting the multiple frame members to each other. The design support method is characterized in that the reinforcement step is a step of setting the reinforcement portion in a portion corresponding to the connection portion of each of the frame members that are connected to each other so as to include the reinforcement portion.

5. A frame member design support device, Having an arithmetic unit, The aforementioned arithmetic unit, For a model of a frame member having an inner part having a closed cross-sectional structure with a polygonal cross-section and an outer part that cooperates with the inner part to form a closed cross-sectional structure with a polygonal cross-section, the distribution of stiffness indices on the model when a load is applied to a specific load point is calculated by performing structural analysis using the finite element method. The calculated stiffness index is divided into multiple ranges, A design support device characterized by identifying a portion of the frame member that has been modeled as a reinforcement area to be reinforced, where the distance between the portion of the inner ridge where the stiffness index within a predetermined range is located and the load input point differs by a predetermined amount or more from the distance between the portion of the outer ridge where the stiffness index within a predetermined range is located and the load input point.

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